On Quasi-Modular Pseudometric Spaces and Asymmetric Uniformities
Abstract
We introduce and analyze quasi-modular pseudometric spaces: structures generated by left/right (generally non-symmetric) Luxemburg-type gauges coming from one-sided modulars. This relaxes symmetry in Chistyakov's modular metric setting and places it within the context of quasi-metrics and quasi-uniform spaces. We develop the basic theory: induced (quasi-)topologies and quasi-uniformities; unit-ball characterizations; and Cauchy notions tailored to asymmetry. We give criteria for completeness, precompactness, and compactness, and prove bicompletion results. A symmetrization principle relates the asymmetric gauges to a canonical modular space; under mild $\Delta_2/\nabla_2$-type hypotheses, symmetrized and bicomplete constructions agree. Categorically, we treat these spaces as Lawvere-enriched objects and describe symmetrization as a Kan-style construction in the enriched setting; the induced entourages admit an Isbell-style uniform interpretation. Applications cover weighted and generalized Orlicz models (including variable-exponent and double-phase growth), asymmetric function spaces built from positive/negative parts, and directed-graph energies with time-dependent costs. These examples yield modular Sobolev-type estimates and demonstrate fixed-point and stability principles for directional media. Overall, this setting unifies analytic, topological, and categorical perspectives for non-symmetric variational problems and provides practical criteria for compactness, duality, and well-posedness in asymmetric settings.